Property revaluations are in progress, and area officials expect some properties to see a decrease in tax value.

Onslow County Tax Administrator Harry Smith said Wednesday that he expects homes that are larger than 2,000 or 2,500 square feet that were sold after 2010 for less than the home was valued at in 2009 to see a decrease.

Revaluations don’t affect all properties the same, he said. Some properties will see a slight increase in their tax value and others will decrease slightly but Smith doesn’t expect the revaluations to be nearly as dramatic as those in 2009.

Property values will be determined by comparing sales of similar property. For example, properties in a waterfront community are compared to waterfront properties that have sold and downtown Jacksonville properties will be compared to the sales price of other downtown properties.

Smith told Onslow County Commissioners this week the 2014 reappraisal is likely to reduce the overall tax base. He also said that real estate makes up 86 percent of the property tax in the area. Motor vehicles follow at 8 percent.

The estimated assessed values for the area for fiscal year 2013-14, which is the most recent estimate, will be approximately $19.3 billion, according to information the Tax Office presented to the Board of Commissioners in a recent special meeting. Of that, OnslowCounty real estate accounts for approximately $11.8 billion while Jacksonville real estate counts for approximately $3 billion.

All properties in OnslowCounty — commercial, residential, in a municipality, in the county and farmland — will be re-evaluated, and property owners will be notified of their new assessed tax value by the end of January or in early February.

Smith said the process has been in progress for a while and typically takes about 18 months for an evaluation like this year’s.

“We visit some properties; we don’t visit each property this time,” he said.

Instead of going door-to-door, tax officials will be verifying property characteristics, making sure all new property records are included and using aerial photography and software to detect building changes, Smith said. If changes are detected, an appraiser is sent out to verify the changes.

While some properties will be visited, Smith said property owners will not be notified in advance of when the appraiser will be visiting.

All property will be re-evaluated by Jan. 1. The tax value would be used for the 2014-15 fiscal year.

But it won’t be over then.

Smith said that by the time one reevaluation is over, it’s time to start the next one.